Jakarta Mail erroneously assumes that classes can be loaded from Thread#getContextClassLoader

api/src/main/java/jakarta/mail/Session.java

@@ -255,7 +255,7 @@ private Session(Properties props, Authenticator authenticator) {
  this.authenticator = authenticator;
  this.streamProvider = StreamProvider.provider();
 
- if (Boolean.valueOf(props.getProperty("mail.debug")).booleanValue())
+ if (Boolean.parseBoolean(props.getProperty("mail.debug")))
  debug = true;
 
  initLogger();
@@ -983,21 +983,20 @@ public void load(InputStream is) throws IOException {
  }
 
  // next, add all the non-default services
- ServiceLoader<Provider> sl = ServiceLoader.load(Provider.class);
+ ServiceLoader<Provider> sl = ServiceLoader.load(Provider.class, cl.getClassLoader());
  for (Provider p : sl) {
  if (!containsDefaultProvider(p))
  addProvider(p);
  }
 
  // + handle Glassfish/OSGi (platform specific default)
- if (isHk2Available()) {
- Iterator<Provider> iter = lookupUsingHk2ServiceLoader(Provider.class.getName());
- while (iter.hasNext()) {
- Provider p = iter.next();
- if (!containsDefaultProvider(p))
- addProvider(p);
- }
+ Iterator<Provider> iter = lookupUsingHk2ServiceLoader(Provider.class, cl.getClassLoader());
+ while (iter.hasNext()) {
+ Provider p = iter.next();
+ if (!containsDefaultProvider(p))
+ addProvider(p);
  }
+
 
  // load the META-INF/javamail.providers file supplied by an application
  loadAllResources("META-INF/javamail.providers", cl, loader);
@@ -1006,27 +1005,26 @@ public void load(InputStream is) throws IOException {
  loadResource("/META-INF/javamail.default.providers", cl, loader, false);
 
  // finally, add all the default services
- sl = ServiceLoader.load(Provider.class);
+ sl = ServiceLoader.load(Provider.class, cl.getClassLoader());
  for (Provider p : sl) {
  if (containsDefaultProvider(p))
  addProvider(p);
  }
 
  // + handle Glassfish/OSGi (platform specific default)
- if (isHk2Available()) {
- Iterator<Provider> iter = lookupUsingHk2ServiceLoader(Provider.class.getName());
- while (iter.hasNext()) {
- Provider p = iter.next();
- if (containsDefaultProvider(p)) {
- addProvider(p);
- }
+ iter = lookupUsingHk2ServiceLoader(Provider.class, cl.getClassLoader());
+ while (iter.hasNext()) {
+ Provider p = iter.next();
+ if (containsDefaultProvider(p)) {
+ addProvider(p);
  }
  }
+
 
  /*
  * If we haven't loaded any providers, fake it.
  */
- if (providers.size() == 0) {
+ if (providers.isEmpty()) {
  logger.config("failed to load any providers, using defaults");
  // failed to load any providers, initialize with our defaults
  addProvider(new Provider(Provider.Type.STORE,
@@ -1388,22 +1386,19 @@ EventQueue getEventQueue() {
 
  private static final String OSGI_SERVICE_LOADER_CLASS_NAME = "org.glassfish.hk2.osgiresourcelocator.ServiceLoader";
 
- private static boolean isHk2Available() {
+ @SuppressWarnings({"unchecked"})
+ private <T> Iterator<T> lookupUsingHk2ServiceLoader(Class<T> factoryId, ClassLoader loader) {
+ Class<?> target;
  try {
- Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME);
- return true;
+ target = Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME, false, loader);
  } catch (ClassNotFoundException ignored) {
+ return Collections.emptyIterator();
  }
- return false;
- }
-
- @SuppressWarnings({"unchecked"})
- private <T> Iterator<T> lookupUsingHk2ServiceLoader(String factoryId) {
+
  try {
  // Use reflection to avoid having any dependency on HK2 ServiceLoader class
- Class<?> serviceClass = Class.forName(factoryId);
+ Class<?> serviceClass = Class.forName(factoryId.getName(), false, loader);
  Class<?>[] args = new Class<?>[]{serviceClass};
- Class<?> target = Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME);
  Method m = target.getMethod("lookupProviderInstances", Class.class);
  Iterable<T> result = ((Iterable<T>) m.invoke(null, (Object[]) args));
  return result != null ? result.iterator() : Collections.emptyIterator();

api/src/main/java/jakarta/mail/util/FactoryFinder.java

@@ -33,46 +33,66 @@ class FactoryFinder {
  * @throws RuntimeException if there is an error
  */
  static <T> T find(Class<T> factoryClass) throws RuntimeException {
+ T result;
+ result = find(factoryClass, Thread.currentThread().getContextClassLoader());
+ if (result != null) {
+ return result;
+ }
+
+ result = find(factoryClass, factoryClass.getClassLoader());
+ if (result != null) {
+ return result;
+ }
+
+ result = find(factoryClass, ClassLoader.getSystemClassLoader());
+ if (result != null) {
+ return result;
+ }
 
+ throw new IllegalStateException("No provider of " + factoryClass.getName() + " was found");
+ }
+
+ private static <T> T find(Class<T> factoryClass, ClassLoader loader) throws RuntimeException {
  String factoryId = factoryClass.getName();
 
  // Use the system property first
  String className = fromSystemProperty(factoryId);
  if (className != null) {
- T result = newInstance(className);
+ T result = newInstance(className, factoryClass, loader);
  if (result != null) {
  return result;
  }
  }
 
  // standard services: java.util.ServiceLoader
- T factory = factoryFromServiceLoader(factoryClass);
+ T factory = factoryFromServiceLoader(factoryClass, loader);
  if (factory != null) {
  return factory;
  }
 
  // handling Glassfish/OSGi (platform specific default)
- if (isHk2Available()) {
- T result = lookupUsingHk2ServiceLoader(factoryId);
- if (result != null) {
- return result;
- }
+
+ T result = lookupUsingHk2ServiceLoader(factoryId, factoryClass, loader);
+ if (result != null) {
+ return result;
  }
- throw new IllegalStateException("Not provider of " + factoryClass.getName() + " was found");
+
+ return null;
  }
 
  @SuppressWarnings({"unchecked"})
- private static <T> T newInstance(String className) throws RuntimeException {
- ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+ private static <T> T newInstance(String className, Class<T> factoryClass, ClassLoader classLoader) throws RuntimeException {
  checkPackageAccess(className);
- Class<T> clazz = null;
  try {
+ Class<T> clazz;
  if (classLoader == null) {
  clazz = (Class<T>) Class.forName(className);
  } else {
- clazz = (Class<T>) classLoader.loadClass(className);
+ clazz = (Class<T>) Class.forName(className, false, classLoader);
  }
- return clazz.getConstructor().newInstance();
+ return clazz.asSubclass(factoryClass).getConstructor().newInstance();
+ } catch (ClassCastException wrongLoader) {
+ return null;
  } catch (ReflectiveOperationException e) {
  throw new IllegalArgumentException("Cannot instance " + className, e);
  }
@@ -85,44 +105,43 @@ private static String fromSystemProperty(String factoryId) {
 
  private static final String OSGI_SERVICE_LOADER_CLASS_NAME = "org.glassfish.hk2.osgiresourcelocator.ServiceLoader";
 
- private static boolean isHk2Available() {
+ @SuppressWarnings({"unchecked"})
+ private static <T> T lookupUsingHk2ServiceLoader(String factoryId, Class<T> factoryClass, ClassLoader loader) {
+ Class<?> target;
  try {
- Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME);
- return true;
+ target = Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME, false, loader);
  } catch (ClassNotFoundException ignored) {
+ return null;
  }
- return false;
- }
 
- @SuppressWarnings({"unchecked"})
- private static <T> T lookupUsingHk2ServiceLoader(String factoryId) {
  try {
  // Use reflection to avoid having any dependency on HK2 ServiceLoader class
- Class<?> serviceClass = Class.forName(factoryId);
+ Class<?> serviceClass = Class.forName(factoryId, false, loader);
  Class<?>[] args = new Class<?>[]{serviceClass};
- Class<?> target = Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME);
  Method m = target.getMethod("lookupProviderInstances", Class.class);
  Iterable<?> iterable = ((Iterable<?>) m.invoke(null, (Object[]) args));
  if (iterable == null) {
  return null;
  }
  Iterator<?> iter = iterable.iterator();
- return iter.hasNext() ? (T) iter.next() : null;
+ return iter.hasNext() ? factoryClass.cast(iter.next()) : null;
  } catch (Exception ignored) {
  // log and continue
  return null;
  }
  }
 
- private static <T> T factoryFromServiceLoader(Class<T> factory) {
+ private static <T> T factoryFromServiceLoader(Class<T> factory, ClassLoader loader) {
  try {
- ServiceLoader<T> sl = ServiceLoader.load(factory);
+ ServiceLoader<T> sl = ServiceLoader.load(factory, loader);
  Iterator<T> iter = sl.iterator();
  if (iter.hasNext()) {
- return iter.next();
+ return factory.cast(iter.next());
  } else {
  return null;
  }
+ } catch (ClassCastException wrongLoader) {
+ return null;
  } catch (Throwable t) {
  // For example, ServiceConfigurationError can be thrown if the factory class is not declared with 'uses' in module-info
  throw new IllegalStateException("Cannot load " + factory + " as ServiceLoader", t);